Simplify the following expression: $n = \dfrac{q^2 + 14q + 45}{q + 5} $
Explanation: First factor the polynomial in the numerator. $ q^2 + 14q + 45 = (q + 5)(q + 9) $ So we can rewrite the expression as: $n = \dfrac{(q + 5)(q + 9)}{q + 5} $ We can divide the numerator and denominator by $(q + 5)$ on condition that $q \neq -5$ Therefore $n = q + 9; q \neq -5$